As published in the journal Water Research, joint work led by Jennifer Gentry-Shields in the Stewart lab investigates the role of DOM as an inhibitor of qPCR in natural waters. This collaborative effort of recent graduates Jennifer Gentry-Shields (PhD 2012) and Angela Wang (MSPH 2011), showed that qPCR inhibition increased with increasing levels of fluorescent DOM, based on a PARAFAC analysis of fluorescent DOM in stream water.

High school teacher Bruce Taterka will join our 2013 Arctic Expedition thanks to the NSF funded PolarTREC program. PolarTREC (Teachers and Researchers Exploring and Collaborating) is a program in which K-12 teachers participate in hands-on field research in the polar regions. Bruce teaches at West Morris Mendham High School in Mendham NJ. Read more about Bruce and the project goals here and news story here.

Recent climate change has increased arctic soil temperatures and thawed large areas of permafrost, allowing microbes to convert previously frozen carbon into the greenhouse gas carbon dioxide (CO2). Furthermore, soil destabilization from melting ice has caused “thermokarst failures,” soil slumping over a large area. This increases exposure of buried carbon and also releases it to surface waters. We are working to understand how and how quickly this newly exposed carbon can be converted to CO2. Our first paper on this process is now published online. We studied seven thermokarst failures on younger to older landscapes and found that thawed soil carbon in sunlight is at least 40% more susceptible to conversion than carbon still in the dark.

Our study has implications for the debate on how climate change in the Arctic will ultimately affect global temperatures. We know that permafrost soils have the potential to double the amount of carbon in the atmosphere on a timescale similar to human inputs of greenhouse gases. What we need to understand are the factors that control the conversion of this carbon once it moves from soils to surface waters, and our study is a step in that direction.